Shell Programming and Scripting

well i have this file here:

<XML>
<pregate xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<system_c>HPREGATE</system_c>
<trans_c>HSPG</trans_c>
<trans_dt>20060105161333</trans_dt>
<user_id_m></user_id_m>
<func_c>C</func_c>
</pregate>
</XML>

i want to substitue pregate with record and also trans_c with trans_b and func_c with func.

i use this sed coding here but i can only get the first one substitute which is the pregate to record. the rest of them is not substitute.

sed s/pregate/Record/ <pre_xml.txt > pre_xml.txt.tmp
sed s/trans_c/trans_b/ <pre_xml.txt >> pre_xml.txt.tmp
sed s/func_c/func/ <pre_xml.txt >> pre_xml.txt.tmp

im doing this in shell script...
hmm..got any idea??

$ sed -e 's/pregate/Record/g' -e 's/trans_c/trans_b/g' -e 's/func_c/func/g' test
<XML>
<Record xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<system_c>HPREGATE</system_c>
<trans_b>HSPG</trans_b>
<trans_dt>20060105161333</trans_dt>
<user_id_m></user_id_m>
<func>C</func>
</Record>
</XML>

thanks very much !